Ferrari’s bold choice in Mexico: why the SF-25 features wide-open cooling gills. Ferrari has opened the gills on the SF-25 in Mexico to improve engine cooling at high altitude.

In Mexico, Ferrari has opened the cooling gills on the SF-25 to improve airflow and ease the strain on the power unit, which faces a particularly tough challenge due to the circuit’s unique characteristics. The Mexican Grand Prix venue is one of the most demanding tracks for Formula 1 cars, mainly because of its altitude — a remarkable 2,285 metres above sea level. Contrary to what one might think, altitude plays a crucial role in car performance, forcing teams to adopt unusual setups compared to other circuits.

At such heights, the air is much thinner — around 25 to 30 percent less dense than normal. Lower air density means fewer molecules hitting the car’s surfaces, significantly changing how it behaves on track.

For this reason, teams run wings with extremely high downforce levels — similar to those used in Monaco — even though the Mexican circuit’s layout is fast and flowing. Another major issue caused by altitude is engine cooling. Because there’s less air available, the power units receive reduced cooling, putting additional stress not only on the engine itself but also on all components that rely on airflow, such as the brakes, which are exposed to very high temperatures.

From an aerodynamic perspective, teams therefore opt for high-downforce setups, while for cooling they adopt dedicated solutions. In particular, the engine cover area features wide-open ventilation gills designed to help lower the power unit’s operating temperatures. This has led to some of the most extreme and generous cooling openings of the season, with each team interpreting the concept differently and offering unique technical insights.

McLaren has attracted attention for its approach, showing noticeably smaller air outlets on the MCL39 compared to its rivals — a sign of the car’s excellent thermal efficiency. Opening large gills certainly helps cooling, but it also negatively affects aerodynamics by disturbing the airflow and pressure around the engine cover. Nevertheless, the demanding conditions in Mexico City leave teams with little choice, as both braking systems and engines face intense thermal stress throughout the weekend.

Will we see record top speeds?

Thinner air also means lower drag. Despite the high-downforce wings, cars are still able to reach some of the highest top speeds of the entire championship. Although the main straight is not the longest on the calendar, the reduced air resistance caused by altitude allows the cars to achieve remarkable straight-line speed — possibly even setting new records in the ground-effect era.

While modern Formula 1 power units are incredibly advanced and efficient, reliability cannot be taken for granted. The extreme altitude of the Autódromo Hermanos Rodríguez remains a critical variable that could still create unexpected challenges during the weekend.